With very poor weather conditions and difficult ground conditions, turnout has been delayed on most beef farms around the country. This has put huge pressure on sheds, where calving is in full swing on spring-calving farms.

The important thing is that cattle are turned out as soon as ground conditions allow and now is the time to plan for this to happen.

This will reduce pressure on housing and fodder supplies, but more importantly it will kickstart paddocks into action. It also reduces costs and increases weight gain.

During winter, many weanlings only gain the bare minimum (0.6kg/day) while still receiving 2-3kg of meal (See Table 1). These weanlings will have huge potential to gain liveweight at grass. The driest fields that were closed up first in the autumn should be grazed first in the next few weeks. On most farms we can split grass covers into three categories:

1 Heavy covers (1,200+kg) 9cm+.

2 Medium covers (500-1200kg) 6-8cm.

3 Light covers (<500kg) 4-6cm.

Here we outline management requirements for each category:

1 Heavy covers

These are more than likely the first fields closed up in the autumn around early October and therefore should be the first fields grazed in the spring. They will have accumulated some grass over the winter months; some swards can grow up to 5kg DM/ha/week in suitable conditions. This winter was quite mild, so we would expect to have some growth during this time. If these fields were not grazed out fully in the autumn, there may be an accumulation of dead matter at the base of the sward. While this is still very digestible grass (up to 70DMD, better than most grass silage this year) it is very important to graze this sward tight and clean it out completely on the first grazing in spring. If this dead matter is allowed to accumulate after first or second grazing it will reduce the quality of grass grown in subsequent rotations. More importantly, it will reduce the growth potential of the field as this dead matter will not capture sunlight or take in nutrients to grow.

If these heavy covers are not grazed, they will not grow to their potential and will have a delayed start.

Dos

  • Graze heavy covers first.
  • Graze out tight

    • Don’ts

  • Delay turnout of stock on to these covers.
  • Spread slurry on these covers.
  • Move stock on early without grazing out fully.

    • 2 Medium covers

    These fields would have been closed up around late October or the first week of November. These are the fields that will respond best to fertiliser in spring. If slurry can be spread via trailing shoe, these covers could get slurry instead of chemical N as the trailing shoe enables grazing in a shorter time frame than the conventional splash plate. These fields will then be ideal to graze in two to three weeks. Grazing these swards too quickly will mean you will run out of grass quite quickly and finish the first rotation ahead of time.

    Dos

  • Target medium covers with fertiliser, or trailing shoe applied slurry

    • Don’ts

  • Graze these swards first in the rotation.
  • Apply slurry with splash plate to these medium covers.

    • 3 Light covers

    These fields will have been the last ones closed up from mid-November onwards and will have only in the region of 4-5cm (>500kg DM). These fields are ideal for slurry application as no grass will be damaged in the slurry spreading process. Spread in ideal conditions (dull, damp, cold) in spring, 2,500 gallons of cattle slurry can produce up to 24 units of nitrogen.

    Spreading, for instance, on a dry sunny day in July will result in reaping 6 units or possibly none. Aim slurry to silage ground to replace P and K offtakes and also reduce the amount of chemical nitrogen required for a silage crop. It will also take probably three to four weeks before these can be grazed, so the time interval between spreading and grazing would be ideal.

    Dos

  • Apply slurry to light covers as early as ground conditions allow.
  • Aim to spread slurry during damp, dull conditions.

    • Don’ts

  • Spread fertiliser on light covers
  • Graze light covers first

    • Spring N application

    Nitrogen is one of the most important nutrients and its application has a direct effect on DM yield. It can produce a timely boost to growth in early spring to help getting cattle out to grass and keep them out. The response to nitrogen in spring can be as high as 1kgN/ 15kg DM grass. A bag of 27.5 CAN contains 13.5kg of nitrogen so it has the potential to grow 202kgs DM grass.

    Response rates to nitrogen (grass dry matter per kg N applied)

    January to February: 0 – 10 kg DM.

    March: 0 – 25kg DM.

    April – May: 15 – 50

    June – August: 15 – 35

    September: 15 – 25

    Response rates will vary from year to year due to temperature, sunshine, rainfall, ground conditions, type of grass sward, reseed or not, etc.

    Top tips for fertiliser application in spring

  • Target your early nitrogen applications to your most productive swards as they will give you the best response: recently reseeded swards, ryegrass swards, fields with medium covers (5-7cm), and fields that are high for all other nutrients ie P, K and lime
  • Wait for soil temperatures to reach a consistent 5-6°C before spreading. This date may vary from year to year.
  • Don’t overdo it on the first application – 23-27 units of N (a bag of CAN or a half-bag of urea) is sufficient for the first application.
  • Urea is cheaper than CAN, but needs the correct conditions for application – cold and damp. As of January 2020, CAN (270kg N/t) costs €250/t, which equates to 92c/kg N. Urea (460kg N/t) costs €330/t, which equates to 71c/kg N.
  • Take a look at your most recent soil tests to determine what P and K status is like across the farm. Fields deficient in phosphorus, potassium and lime would be better served with a compound application like 18:6:12 or pasture sward or better still target these for slurry application.
  • Avoid spreading high-potassium (K) compounds in spring where lactating animals are grazing. High soil K can displace magnesium and lead to the onset of grass tetany.
  • Leave 10 days between slurry and fertiliser applications as slurry creates anaerobic conditions and could lead to the loss of nitrogen.
  • Lime increases soil PH and this in turn can lead to losses of ammonium. Leave three to six months between liming and urea/slurry applications to reduce potential losses.